General tube questions:

Doug's Tubes tube specific questions:


Return Policy:

Tube amp questions:

What do balanced triodes mean? Do I need them?
Dual triode preamp tubes like the 12AX7 really have two separate tubes inside one glass envelope. When the plate current draw of each triode is the same(as evaluated by our VTV testers), we refer to that as having balanced triodes. These may or may not also have the same gain on each triode but are still considered balanced. Chances are that these are not required for your particular circuit. What we have observed after testing 1000's of preamp tubes using the Vacuum Tube Valley dual triode characterizer is that tubes with balanced triodes seem to be more consistent with a standard specification tube as to gain and low noise and microphonics.

What is tube rolling?
Tube rolling is the process of trying out a number of tubes in the same spot and selecting the one that sounds best to you. Some folks have found this to be helpful in optimizing the tone for their amp.

What do the numbers written on my preamp tube with a sharpie mean?
The numbers on your preamp tube represents the gain of each triode as measured on our Vacuum Tube Valley dual triode characterizers(VTV). The gain scale is not to be construed as the actual Mu of the tube, but is an arbitrary scale used by VTV that helps us grade each preamp tube and compare them to each other. Since many of the preamp tubes we sell have dual triodes, you'll find two numbers on the side of the tube. The higher the number, the higher the gain. We consider 110/110 or more per side to be HIGH GAIN tubes.

How much will it cost to re-tube my amp?
There is no set or average amount. It depends on the tubes, and it depends on the amp. An Epivavle Jr. can run only about $20, and where as any Mesa Dual Rectifier can run up to about $150+. Of course, NOS/ANOS will bring you price up a considerable amount.

Should I use an amp tech to change my tubes?
Nope. The only tech related tube issues you should have is re-biasing the amp, which is needed each time your replace tubes (unless you can replace them with new tubes that have the same current draw). We can do this.

How do I change the tubes in my amp? Do I need an amp tech to change tubes?
Changing tubes is a lot easier than most people think, and it can even be done by people who consider themselves newbies. Once you have removed the back cover of the amp:

Power Tubes

1) Grip the base of the power tube with your finger tips, and cup the glass top with the palm of your hand.
2) Gently start removing the tube in a circular motion.
3) Do it carefully as to not to damage or break the tube.

Preamp Tubes

1) Carefully twist off the preamp covers. (Its common to break a preamp by taking the cover off to harshly).
2) Gently start removing the tube in a circular motion.
3) Do it carefully as to not to damage or break the tube.

What do ECC81, ECC82, ECC83, & ECC803S mean?
These are the european ways of identifying what we consider a 12AT7(ECC81), 12AU7(ECC82), and a 12AX7(ECC83).

What do the numbers written on the white label on my power tubes mean?
The numbers on the white label shown on your power tube boxes represent the plate current and transconductance of that particular tube (as evaluated on our Maxi-Matcher testers). We try and match the plate current and transconductance as close as possible (at least 5% & 10% respectively).

Do you test for low noise and microphonics?
Low noise and microphonics is part of our regular standard testing and screening of every tube. Therefore, we do not charge a premium for low noise or microphonics.

What is the difference between Standard Test and Balanced Triodes?
Standard Test describes the normal testing that we do with every tube. We test for low noise, microphonics, gain, and durability of the tube with every test. Find out more about balanced triodes.

How does your ratings system work?
Early Distortion (Groove Tubes - # 1-3) is best for a softer attack, and those who play a lot of rock and blues solos.

Average Distortion (Groove Tubes - # 4-7) is great for your normal all around tone - for those who want some versatility in their sound.

Late Distortion (Groove Tubes - # 8-10) is chosen for those who want their sound dynamic and clean - especially Jazz and Bass players.

How often do I change my tubes?
New tubes may be needed when a problem arises, such as popping, crackling, or if you notice an overall degradation of tone. Average tube life depends on the use your equipment gets, and how hard your gear is used.

How do I know if I have a bad tube?
If you hear a hissing or popping, it probably is a bad tube.

What should you tell us before placing an order?
You can let us know what style of music you primarily play, and what amplifier or preamp the tubes you are ordering will be installed in. This insures that you will get the tubes that match your sound. We encourage everyone to call us if you have any questions, so we can help you get the most out of your purchase.

How do I place an order?
It's easy. We have integrated a shopping cart into the website, so you can order singles, matched pairs or quads. You can also correct and update the shopping cart if you want. You can email us at djp@optonline.net to place an order, or you can call us at 516-314-0357 to place an order.

What forms of payment do you accept?
In addition to personal checks and money orders, we accept Visa, Mastercard, and Discover, and Paypal.

How long will my order take to ship?
All domestic orders are shipped USPS at the end of each business day Monday thru Friday at 5pm EST, excluding holidays. Tracking numbers are sent through Paypal and USPS that evening. Orders received after 12 noon are shipped the next business day, subject to inventory availability. For international orders, Express Mail International usually takes 3-5 days depending where you live.

Do you accept international orders?
Yes! Doug's Tubes ships worldwide to any location serviced by the US Post Office. Email djp@optonline.net for a shipping quote. We suggest you use Express Mail International. Although it is more expensive, it comes with $200 insurance enables you to track your shipment.

My order is over $105 dollars and the shopping cart it still charging me shipping. What gives?
All domestic orders over $105 receive free shipping. Select the shipping method of your choice, the shopping cart automatically deducts $6.90 on the product line.

What does the discount code in the shopping cart mean?
If you are shipping somewhere in the United States, and your order is over 105.00 dollars, it is no longer necessary to manually add a discount code, it's calculated automatically.

I still haven't received a shipping confirmation email yet. What do I do?
If it has been a complete business day and you still haven't received a USPS confirmation, please email us and let us know.

How do I check the status of my order?
After you have received your USPS shipping confirmation email, please go here to check on the location of your package.

Why is there still a $2.75 fee?
This is a handling fee. Shipping costs $6.90. All packages are insured.

What is your warranty policy?
Depending on the tube manufacturer, it can be from 30 days to 6 months. Please check our return policies for specific brands.

If I have a bad tube, what do I do?
Please email us and tell us about your problem. Once you have let us know about your problem, please send the tubes back USPS First Class to:

Doug's Tubes, Inc.
188 Tally Lane
Wantagh, NY 11793

What do the "options" mean for preamp tubes?
We've allowed you to select additional options for your preamp tubes when needed:

Balanced:  When the plate current draw of each triode is the same, we refer to that as having balanced triodes. 

High Gain:  Tubes that measured to have higher gain.

Matched:  Each triode of the preamp tube has matching gain.

Doug's Tubes, Inc.

188 Tally Lane

Wantagh, NY 11793


Mon-Fri 11am-5pm EST


Call to place an order:



Email for tube recommendations:


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